Performance Over Time and Durability Assessment …
285
Fig. 4 Trend percentage of
thermal resistances in the
sample at the door (the curve
relating to the coated section
with artificial stone is in
yellow and the one in brown
is with natural stone)
Thermal resistance with natural stone cladding (NAT)
Thermal resistance with artificial stone cladding (ART)
Specifically, with respect to the thermal resistance value before the accelerated
ageing:
– t 1 in both solutions show a halving of the thermal resistance;
– at t 2 , the thermal resistance of the section of the natural stone showed a decrease of
approximately 22%, while that of the artificial stone section decreased by approximately 9% (and therefore a performance decay of around 13% less than natural
stone).
6 Concluding Remarks
Following the described accelerated ageing, the experimentation above described
showed that:
– considering only the physical degradation, both the natural stone cladding and the
artificial stone cladding did not reveal cracks in the stone, delamination or any
mechanical type effects;
– the cast stone cladding performed, at time zero and as a result of accelerated ageing
cycles, a better thermal behaviour than the natural stone; specifically, the artificial
stone cladding shows a lower thermal conductivity, and after two accelerated ageing cycles, a decay in thermal resistance by approximately 13% less than the of
natural stone;
– the presence of the stone coating generally involved a thermal shock mitigation
effect;
– it is advisable to carry out colorimetric measurements on single-stone blocks in
order to precisely evaluate the colorimetric variations of the coated surfaces; eventually, considering how the moisture content has an impact on the component’s
thermal behaviour and taking into account the porosity of the coating materials, it
is also advisable to assess the progress of thermo-hygrometric behaviour over time
through simulations with the appropriate “Heat and Moisture Transfer” calculation
software.
285
Fig. 4 Trend percentage of
thermal resistances in the
sample at the door (the curve
relating to the coated section
with artificial stone is in
yellow and the one in brown
is with natural stone)
Thermal resistance with natural stone cladding (NAT)
Thermal resistance with artificial stone cladding (ART)
Specifically, with respect to the thermal resistance value before the accelerated
ageing:
– t 1 in both solutions show a halving of the thermal resistance;
– at t 2 , the thermal resistance of the section of the natural stone showed a decrease of
approximately 22%, while that of the artificial stone section decreased by approximately 9% (and therefore a performance decay of around 13% less than natural
stone).
6 Concluding Remarks
Following the described accelerated ageing, the experimentation above described
showed that:
– considering only the physical degradation, both the natural stone cladding and the
artificial stone cladding did not reveal cracks in the stone, delamination or any
mechanical type effects;
– the cast stone cladding performed, at time zero and as a result of accelerated ageing
cycles, a better thermal behaviour than the natural stone; specifically, the artificial
stone cladding shows a lower thermal conductivity, and after two accelerated ageing cycles, a decay in thermal resistance by approximately 13% less than the of
natural stone;
– the presence of the stone coating generally involved a thermal shock mitigation
effect;
– it is advisable to carry out colorimetric measurements on single-stone blocks in
order to precisely evaluate the colorimetric variations of the coated surfaces; eventually, considering how the moisture content has an impact on the component’s
thermal behaviour and taking into account the porosity of the coating materials, it
is also advisable to assess the progress of thermo-hygrometric behaviour over time
through simulations with the appropriate “Heat and Moisture Transfer” calculation
software.